In this work, a synchronized dual-modal imaging system is used for in-vivo, non-contact ophthalmic imaging. The apparatus is comprised of both Photoacoustic Remote Sensing (PARS) and Swept-Source Optical Coherence Tomography (SS-OCT) subsystems. The PARS utilizes a multi-wavelength excitation source to target hemoglobin absorption and an 830 nm interrogation source to detect photoacoustic signals. PARS provides the measurements for computing blood oxygen saturation (sO2) mapping in the mouse and rat eyes. Meanwhile, a 1060 nm SS-OCT is employed to obtain volumetric tissue structure. To our knowledge, this is the first report of non-contact functional photoacoustic imaging in ophthalmic applications.
We present a new technique for improving the temporal stability of the Stimulated Raman Scattering (SRS)-based multispectral pulsed source by decreasing the temperature of the SRS medium. This technique reduces temporal fluctuations of the output SRS peaks, generates stable multiwavelength light, improves repeatability and accuracy of functional measurements. This stabilized temperature-regulated SRS-based source is combined with the wide field of view photoacoustic remote sensing microscope utilizing a telecentric scan lens as an imaging objective. In-vivo functional imaging experiments of the chorioallantois membrane of a chicken embryo (CAM) are performed for validation purposes.
In Photoacoustic Remote Sensing (PARS) microscopy, a pulsed excitation beam is co-focused with a continuous-wave interrogation beam to acquire photoacoustic signals in an all-optical non-contact way. This study implements a resonant deformable mirror (DM) as the active focal control element in PARS. The surface of the DM is deformed by a time-varying actuation force tuned to match the resonance frequency of the defocus mode. In preliminary experiments using the DM as a focusing element, a 5cm focal shift was realized. The Adaptive Optics (AO)-PARS is a promising technology for axial scanning, multi-wavelength imaging, and aberration correction applications.
A hyperspectral photoacoustic remote sensing microscope is used to investigate and image optical absorption contrast in live and resected chicken tissues ranging from 250 nm to 1210 nm highlighting DNA, hemeproteins, and lipids.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.